Telephone-transmitter.



. s'. c. PORTER. TELEPHONE TRANSMITTER. APPLICATION FILED IAN. I8, 1915.

1,201,343. n Patented 0Qt.17,1916.

In Ventor: I

gES PATENT OFFICE.

STEPHEN C. PORTER, OF NEW YORK, N. Y., ASSIGNOR TO THE PORT-O-PHONE CORPO- RATION, OF ESOPUS, NEW YORK, A CORPORATION OF NEW YORK.

TELEPHONE-TRANSMITTER. I

Application filed January 18, 1915.

To all whom it may concern:

Be it known that I, STEPHEN C. PORTER, a citizen of the United States, residing at Brooklyn borough, city of New York, in the county of Kings-and State of New York,-

have invented certain new and useful Improvements in Telephone-Transmitters, of which the following is a specification.

My invention relates to sensitive telephone transmitters of the type used in collecting sounds emanating at a distance from the instrument and my objects are the production of a small, simple, cheaply constructed device having a sound concentracting passage leading to the diaphragm which will'collect sounds from greater distances and convey them to the diaphragm with suflicient force to powerfully actuate the same and clearly reproduce them at the receivingend.

The drawing is a sectional, perspective view of the transmitter.-

The body 1 is made of any suitable material, vulcanite or hard rubber preferred as it is cheap, easily molded or worked and being an insulator simplifies the electrical connections, It has an annular depression 2 gently curving up to the apex 3 in the center.

The cover plate 4 has the slots 5J5 near the edge and the annulus 6 inside the slot line. The carbon back 7 is secured to the cover plate. A filler block 8, having-a central chamber 9 into which the back 7 and annulus 6 projects, is curved at 11 so that when the cover plate, and attached parts, is placed in the case 1 an annular sound passage wlll be formed, larger at the slots than at the mside ends and gradually diminishing to concentrate the sound at the small or d aphragm end. The diaphragm 10 rests on a gasket 12 and is clamped by the annulus 6, V

' the carbon 13 being placed between the back 7 and diaphragm 10. One terminal 14 is connected to the carbon back 7 and the other Specification of Letters Patent.

Patented Oct. 17, 1916.

Serial No. 2,873.

to the metallic filler 8 with which the diaphragm is in electrical contact. Sounds striking the instrument will pass through the annular passage gradually concentrating until they strike the diaphragm with full force.

I The instrument is used in connection with an ordinary battery and receiver and is useful in aiding the deaf to hear and as a sensitive transmitter which will collect sounds occurring within a reasonable distance of it and which does not require the person to speak directly into it as is the common practice.

v I claim 1. In a telephonic transmitter case a single, continuous, curved annular sound passage extending from the edge thereof on an inward curve to the middle portion of the case and gradually decreasing in size from the larger, outer end as it approaches the middle whereby the sound is concentrated.

2. A telephonic transmittercomposed of a body having a single, continuous, curved annular depression therein terminating in a central apex, a cover having circularly disposed slots and a single, continuous, curved annular-flange depending therefrom inside the slot line, a filling block with a central chamber rounded at the lower face with a central opening therein secured to the cover, a diaphragm secured between the filling block and the edge of the annular cover flange, a telephone back secured to the cover, carbon between the diaphragm and back, a line wire leading from the back and a line wire leading from the diaphragm.

In testimony whereof I have aflixed my Witnesses:

ROBERT B. KILLGORE, MAY M. LIPP. 

